He-4 desorption from single wall carbon nanotube bundles: A one-dimensional adsorbate

The desorption of He-4 from single wall carbon nanotube bundles has been me asured for T > 14 K. The adsorbate is approximately described by one-dimens ional adsorption with a binding energy epsilon = 330 K. This binding energy is the largest measured for any charge neutral surface. Theoretical studie s predict such a high binding energy for an adsorbate located in the inters titial sites of the single wall carbon nanotube bundles, We find a He-4 int erparticle distance of similar to 3 nm at 14.2 K at a pressure of 10(-6) to rr.